Thank you so much for giving us the opportunity to help you .. we will try our best:

YOUR MOM Loves you! What a blessing! You are so lucky there, be happy for that...
Your sister (8 years old) probably loves your dad and has chosen a "side to be", not a person to love or not love. I am sure, inside of her there is a light that one day is going to come on, she'll discover that is ok to love her dad and you too!! You wait and see.
YOUR DAD is probably dealing with some issues of his own too. It takes a lot of streight and courage to look inside ourselves. Pray for him so that he can open his heart and heal himself one day.

Lots of love

gab